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Francisco de Goya (Spanish, 1746-1823)
The Sleep of Reason Produces Monsters (1797-98)


Etymology (the historical origin or derivation of a word): Greek: logikē or logikos = well-ordered speech, well-functioning reason, systematic thought, intelligibility. Compare the prominent Greek concept logos = speech, discourse, word, thought, reason, explanatory account, ordering principle, underlying intelligibility.

2. Historical origin: The ancient Greek philosopher Aristotle (384-322 BCE) is generally acknowledged as the “father of Western logic.” Certainly, the pre-Aristotelian Greek intellectual tradition (Presocratic philosophers, the Sophists, Socrates, Plato, Parmenides, Pythagoras, Euclid, Archimedes, Zeno, etc.) had developed and utilized logical techniques (and, in the case of the Sophists, fallaciously deceptive techniques aimed at pragmatic success rather than truth). However, Aristotle far surpassed his philosophical predecessors by establishing logic as 1) the fundamental intellectual standard and methodological framework of scientific inquiry, and 2) an autonomous, basic branch of all philosophical inquiry insofar as logical reasoning is a prerequisite skill for all fields of study or research. Accordingly, he transformed the concepts and principles of correct reasoning into a multi-dimensional system of scientific inquiry and discovery. Aristotle interprets logic as an indispensable (ineliminable, prerequisite) methodological foundation for every form of scientific knowledge and a necessary instrument in any theoretical or practical inquiry. Hence, later editors of his five logical treatises (see below) entitled them to organon = tool, instrument, apparatus, or method.

Aristotelian logic is often referred to as traditional or syllogistic logic (see Hurley, chaps. 4-5).

3. Scientific standard: From an academic or educational perspective, logic is the standards or principles of correct reasoning. Logical principles, norms, rules, or standards function as normative criteria for evaluating claims to knowledge and all forms of reasoning. Accordingly, as a scientific standard, logic consists of a body of systematic principles, methodical techniques, technical terminology, and logical theory. In this context, logic is an academic discipline, an independent field of study, and basic branch of Western philosophy devoted to classifying, analyzing, and evaluating arguments (or inferences). Therefore, logic involves critical judgment* since it distinguishes between (and thereby evaluates) correct and incorrect reasoning. Following from this quality, logic is primarily concerned with the form (structure or pattern) of reasoning, not with the content (particular subject matter) of arguments. This scientific definition of logic stresses its theoretical, methodological, formal and normative nature.

* The word “critical” derives from two Greek roots, kriticos = discerning judgment + kriterion = standards. Etymologically, therefore, the term implies the development of discerning judgment based on standards.

4. Practical Art or Performance Skill: Logic is defined from a practical perspective as the acquired intellectual capacity to appropriately apply logical principles and methods to a wide range of theoretical and practical problems: personal, professional, academic, legal, social, scientific, political, interpersonal, communal, etc. Consequently, logic defined as a practical, performative competence is exhibited in a variety of interrelated reasoning skills (skill set):

  • Evidential reasoning: An interest in, capacity for, and practice of reasoning on the basis of relevant and sufficient evidence. One skilled at determining the suitable standards for identifying what sort of evidence is relevant to a particular problem, and how much weight and significance to place on any given piece of evidence. One who uses logical techniques appropriately to form well-founded judgments of all kind (theoretical, practical, affective, etc.). Professional examples: criminal detective work, medical diagnosis, legal judgment, auto repair troubleshooting, advertising and marketing, engineering, etc.
  • Consistent reasoning: A person with a developed sensitivity to, and consequent criticism of, logical inconsistency, contradiction, and incoherence. Like Socratic cross-examination (Greek: elenchus), coherent reasoning discerns how the logical implications of a thesis or concept may lead to a logical contradiction (which is a logical impossibility, like “X and not-X are simultaneously true in every respect). In Latin, this ancient form of logical refutation was termed reductio ad absurdum, meaning, “reduction to non-sense or absurdity.”
  • Analytical reasoning (analysis): The ability to break down complex problems into their component parts. The capacity to precisely distinguish closely related yet easily confused concepts or objects. Analytical reasoning also includes general definitional skills, the capacity to analyze X (a concept, term, word, historical event, perplexing experience, complex problem, personality, etc.) into its diverse yet interrelated semantic senses.
  • Synthetic reasoning (synthesis): The intellectual capacity to frame or place (contextualize) a problem in its broadest context (whether historical, scientific, cultural, social, etc.), perceiving its connection to other problems (realities, events objects, etc.). The ability to problem-solve through creative recourse to similar problems in other areas (see analogical reasoning). The capacity to organize or integrate any identifiable entity into a larger, comprehensive, coherent structure or framework. In the context of dialogue or critical discussion, synthetic reasoning is the ability to perceive emerging patterns or formations of interrelated meanings (cf. the psychological concept of gestalt) in the interactive process of dialogical interplay. In general, synthetic reasoning is an acquired awareness of logical relations on a larger scale.
  • Empirical reasoning (e.g., generalization): The intellectual ability to conceptualize (infer, abstract, extract, draw out) general truths (principles, laws, norms, concepts) on the evidential basis of relevant and sufficient instances (cases, examples). This is a common form of probabilistic reasoning called inductive generalization. In contrast to analogical reasoning, inductive generalization not only identifies hitherto unnoticed similarities between distinct objects or spheres, but also generates a conceptual category or general class under which distinct instances have been subsumed. For example, a young child, upon experiencing only red roses in his or her environment, might draw (mistakenly) the general conclusion that “roses are red,” meaning that all roses share the common characteristic of redness. The child has reasoned from many particular instances of red roses to the general concept that all roses, as members of a class or category, exhibit an identical property (redness) beyond mere resemblance (analogical reasoning).
  • Deductive reasoning: The ability to draw out (infer, deduce) the logical implications or consequences inherent (contained within) in X (concept, event, reality, definition, object, etc.). The general logical capacity to render explicit what is implicit, to perceive implied relations, and to draw out (infer, deduce) logical implications or consequences.
  • Analogical reasoning: The intellectual capacity to perceive pertinent similarities (or relevant resemblances) between different objects (ideas, events, things, etc.) and to reason on the basis of the perceived analogy or comparison. Such perceived similarities may provide grounds (premises) for an argument or may initiate the gradual construction (by a process of abstraction) of a formal concept. Analogical reasoning is exhibited at an early developmental stage but is also utilized at later stages.
  • Explanatory reasoning: Intellectual skill at causal reasoning, such as diagnostic trouble-shooting (auto mechanic), criminal detective work, medical diagnosis, psychiatric counseling, historical interpretation, scientific hypothesizing about the cause of X, everyday explanations of events and behavior, etc. The intellectual ability to provide an account of why X is true, why X exists, why X happened, or why X is happening, i.e., demonstrating the causal basis or raison d’être (reason for being) of X.
  • Abstract reasoning: The very general intellectual capacity to engage in formal (procedural, abstract, conceptual) thinking, i.e., thinking that perceives purely formal relations apart from the specific, particular, concrete content that exhibits such relations. Hence, intellectual abstraction separates or extracts the form from the content. Example: After experiencing car tires, dinner plates, and Frisbees, a young child suddenly realizes (concludes) that they all embody the same geometrical shape or form: circularity. Or, another example, at a particular age we begin to think of purely formal or mathematical relations between numbers (5 + 5 = 10) rather than the concrete content such numbers might designate (5 fingers + 5 fingers = 10 fingers).

5. Attitude or Disposition: One may be logical or illogical in their attitudes or affective dispositional traits. Attitudes tend to be preconscious or unexamined, but they don’t need to be that way. Quite often, specific types of attitudes, and their consequent actions, impede logical reasoning: prejudice, egocentrism, ethnocentrism, blind loyalty, provincialism, dogmatism, psychological defense mechanism, rationalization, stereotyping, superstition, wishful thinking, etc. These illogical attitudes impede the art of objectivity. Therefore, on an attitudinal level, logic is reflected in the following intellectual virtues or rational attitudes:

  • Intellectual open-mindedness: A willingness to consider all sides of an issue and to follow the evidence wherever it leads (to its logical conclusion). Not being dogmatic, that is, willing to fairly consider any counterevidence and in general be open to different arguments and positions. Note Well: Being open-minded does not require that one be dispassionately neutral, nonpartisan (without allegiances or affiliations), indifferent, or lacking emotional, deeply-held commitments. However, one must be constantly self-critical lest reasoned commitments gradually degenerate into entrenched prejudices impervious (not open to any external influence, not penetrable) to counterevidence or counterargument.
  • Intellectual impartiality: Granting, as a matter of logical and moral principle, competing positions or arguments a fair hearing, that is, being fair-minded, without bias, prejudice or preferential treatment. One should bear this logical trait in mind especially when you have very strong feelings regarding an issue. Intellectual impartiality treats all viewpoints alike, without reference to one's vested interests or to the vested interests of family, friends, community or nation. Consequently, intellectual impartiality implies an adherence to normative intellectual standards, without any consideration of advantage to oneself or one's group.
  • Intellectual empathy: The capacity to decenter oneself, that is, to achieve some reflective and disciplined distance from one’s own views in order to look at an issue from another person’s perspective. Cf. the proverbial “walk a mile in my shoes” as a concrete analogy of this mental capacity for role reversal. Not egocentric, or by extension, not ethnocentric. Being conscious of the logical need and benefits of imaginatively adopting the position or perspective of others in order to understand them more genuinely. Intellectual empathy requires a conscious awareness of our egocentric (ethnocentric, provincial) tendency to identify truth with our immediate, given, unexamined, and long-standing beliefs. Intellectual empathy also consist in the logical ability to reconstruct accurately the viewpoints and reasoning of others and to reason from premises, assumptions, and ideas other than one’s own. Lastly, intellectual empathy involves the disciplined practice of recalling occasions in the past when we were wrong despite an intense conviction that we were right. Concomitantly, it also involves the ability to imaginatively project the possibility of our being similarly deceived in the present or future. A representative selection of egocentric mechanisms include: 1) egocentric memory 2) egocentric myopia (shortsightedness) 3) egocentric illusion (subjectivism) 4) egocentric self-righteousness 5) egocentric hypocrisy 6) egocentric oversimplification 7) egocentric blindness 8) egocentric immediacy, and 9) egocentric absurdity.
  • Intellectual autonomy: Involves an internal motivation to be intellectually independent, that is, to affirm one’s beliefs based on the rational ideal of thinking for oneself. Intellectual autonomy implies that one’s beliefs, values, and ways of thinking (worldview) are the result of rational self-determination. An intellectually autonomous person is not dependent on others for the interpretive direction and continuous control of his or her reasoning processes and consequent belief system. Intellectual autonomy is a kind of intellectual conscience (Friedrich Nietzsche’s expression) that carries a strong personal sense of intellectual accountability for one’s views, i.e., a responsibility to justify one’s beliefs, on the basis of credible evidence, to oneself and to others. Intellectual self-discipline is a subset of intellectual autonomy and begets a methodical mindset that develops, disciplines, and trains one’s intellectual attitudes and practices. It is an exercise of constant self-criticism and correction in the light of new evidence, problems, or context. This rigorous intellectual disciplining of distorting attitudes and affects (obstacles or impediments) is required if one is to achieve and practice the autonomous art of rational objectivity. However, this intellectual independence does not preclude (render impossible) a well-founded recognition and respect for genuine intellectual expertise. Reasonable recognition of intellectual authorities should be precisely distinguished from an irrational attitude of uncritical dependence (heteronomy). Contrasted with intellectual heteronomy.
  • Intellectual humility: An awareness of the limits of one's knowledge (cf. Socratic ignorance and cross-examination) and a critical sensitivity to situations in which one's native egocentrism may function self-deceptively. In particular, a conscious awareness and corrective monitoring of the particular biases, prejudices and limitations of one's viewpoint. Moreover, an intellectually humble person only claims to know what he or she actually does know (the opposite of intellectual arrogance, conceit or pretentiousness). Accordingly, it implies a continuous and critical self-examination of one’s claims to knowledge and the absence of inflated intellectual conceit. Consistent, critical self-examination typically leads to informed insight into the logical basis, or lack thereof, of one's beliefs. Intellectual humility does not, however, imply a docile intellectual submissiveness or subservience. It does imply, however, the intellectual and emotional maturity (psychological security) to accept civil criticism without taking it as a personal insult. Finally, intellectual humility involves the intellectual capacity and practice of suspending judgment (Greek: epochê; Cf. Pyrrhonian skepticism, Descartes, and Husserlian phenomenology) on an issue whenever insufficient evidence renders rational evaluation premature.
  • Intellectual courage: The acquired ability to adopt and promote controversial or unusual viewpoints, even in the face of negative consequences from one’s family, friends, community or country. Dramatic historical examples include Socrates, Jesus, Martin Luther, Nelson Mandela and Martin Luther King. Intellectual courage also includes the capacity to critically and fairly examine viewpoints toward which we have strong negative emotions. Consequently, we typically do not give such viewpoints a serious and fair hearing. Intellectual courage also recognizes that ideas traditionally considered false (or even dangerous, absurd, heretical, heterodox, revolutionary, radical, etc.) are, as proven by history, sometimes rationally justified (in whole or in part). Intellectual courage involves an awareness that the personal beliefs inculcated in us through socialization or enculturation are sometimes false or misleading. Intellectual courage does not passively and uncritically accept the conventional beliefs of one’s culture because, among other reasons, unorthodox ideas (e.g., Copernicus’ heliocentric model of the cosmos) traditionally considered dangerous or absurd occasionally turn out to be true. Conversely, unconsciously assimilated cultural orthodoxies (e.g., Aristotelian-Medieval geocentric model of the cosmos) occasionally turn out to be false. Such circumstances call for intellectual courage in order to be true to one’s our own thinking. Societal sanctions or penalties for non-conformity can be severe (imprisonment, torture, death, social segregation, unemployment, etc.).
  • Intellectual integrity: A deeply principled recognition of the need to be authentic or genuine in one's thinking; to be consistently impartial in the intellectual standards one applies; to hold oneself to the same rigorous standards of thinking and evidence to which one holds others, especially intellectual opponents; to practice and live what one professes to be true or advocates for others; and to honestly recognize, and consequently correct, irrational tendencies and logical inconsistencies in one's thinking and practice. A person with intellectual integrity participates in dialogue, critical discussions or debates in good faith, i.e., on the basis of a common commitment to logical standards, principles and methods.
  • Intellectual confidence: A firmly founded confidence that the unencumbered exercise of rationality is in everyone’s long-term, higher interests; that, like Socrates, we should encourage people to think for themselves by developing their own rational skills; that, with sufficient encouragement and instruction, people can learn to form rational viewpoints, draw reasonable conclusions, and think coherently. The sustaining faith that, despite the deep-seated, native, and societal obstacles facing them, people can become—admittedly with considerable effort—reasonable persons who persuade each other through logical interaction. The alternative to rational discussion and dialogue is shortsighted, self-destructive and well known: raw power.
  • Intellectual perseverance: The exercise of critical self-reflection; the capacity to step back, to disengage or detach oneself, and to temporarily suspend judgment about oneself or a specific intellectual problem for the purposes of critical self-examination; the ability to look at one’s beliefs and practices through the eyes of others; a form of reflective self-criticism conducive to clarifying and organizing one’s belief system; not naïve, uncritical, or prereflective, but conscious of the need to maintain intellectual standards and practices despite the difficulties, obstacles, and frustrations; a firm adherence to rational principles despite the irrational opposition of others; a recognition of the rational need to continuously struggle with unresolved intellectual confusion over an extended period of time in order to achieve deeper insight.
  • Intellectual curiosity: A deeply rooted, habitual interest in truths of all kind (scientific, historical, logical, biological, etc.); in continuously learning and expanding one’s intellectual horizons, in the belief that the “life of the mind” illuminates and enriches every sphere of existence; in excavating the subterranean interconnections, typically unnoticed, between distinct types of truth (biological, historical, logical, psychological, etc.); in exploring new domains of reality, experience or knowledge, often adopting novel methods of research or inquiry.

6. Historical Types

  • Aristotelian, traditional, syllogistic, or classical: especially categorical propositions, categorical syllogisms, and assessing deductive validity.
  • Informal: examines the nature, types, and correctness of arguments in natural language.
  • Formal: examines the nature, types, and correctness of arguments in symbolic or formal language (cf. Hurley, chaps. 6-8). Examples: propositional logic, predicate logic, modal logic, fuzzy logic, etc. Sometimes called modern symbolic logic.

B. The Value of Logic

B.1 The General Value of Logic

  • Tool, instrument, or method applicable to numerous theoretical and practical contexts
  • Improvement of analytical and critical reasoning skills
  • Development of conceptual clarity and precision
  • Enhancement of overall problem-solving skills
  • Cultivation of intellectual discipline and organization
  • Broadened range and quality of several language skills (speaking, writing, etc.)
  • Inculcation of attitude and practice of rational objectivity
  • Promotes and facilitates acquisition of truth and knowledge

1. General applications: The formal, structured study of logic should produce several intellectual benefits, including the following:

  • Decreased probability of being deceived, exploited, or manipulated by others (including the mass media, advertisements, politicians, TV, newspapers, radio talk shows, demagogues, propaganda, etc.)
  • Increased ability to clarify and organize one’s belief system (worldview), which typically tend to be half-formed, hazy, and incoherent.
  • Increased skill in assessing arguments and knowledge claims, resulting in an improved ability to critically acquire knowledge.
  • Improved language skills, including writing, reading, speaking, and listening.

2. Academic or educational applications: Although logical skills will improve one’s performance in any academic course, they are especially helpful in math, computer, science, psychology, history, English, law, and foreign language courses

3. Professional or work-related applications: These include problem-solving abilities, communication skills, wide-ranging reasoning and conceptual capabilities, etc.

4. Personal applications: Logical skills enable one to clarify and organize his or her belief system, to critically reflect upon one’s views, to improve basic problem-solving skills, and to avoid self-deception by one’s own faulty reasoning.

5. Interpersonal applications: Logical skills decrease the probability of being deceived by the faulty reasoning of others, improves communication skills, and increases one’s rational impartiality in interactions with others.

C. The Limits of Logic

  • Restrictive utility of logic as a tool or instrument only (not a panacea or cure-all)
  • Logic’s formal or abstract nature (can’t determine one’s substantive values or make life-decisions)
  • Logic can become one-sided or extreme if not balanced by other essential human dimensions (affective, aesthetic, spiritual, sensual, evaluative, ethical, interpersonal, etc.) or if relied on too extensively, or even exclusively.