Describing the Ideal: The Normative and Descriptive Facets of Logic
Is logic normative or descriptive? This question frequently arises in discussions about logic, presenting a challenging dichotomy. However, I find myself unable to firmly choose one over the other. Thus, I often respond, "Yes, it is both normative and descriptive," a typical logician’s answer to a binary question where the option for "both" exists.
First, let's unpack what this question entails. If logic is normative, it functions as a directive force, guiding your thought process, decision-making, and inferential reasoning. A normative theory offers guidance and direction. On the other hand, if logic is descriptive, it assumes the role of an observer, merely documenting the processes of thought, akin to a scientific endeavor aimed at describing and explaining phenomena in the world.
Given this distinction, is logic normative or descriptive? The answer is not straightforward. Logic primarily deals with structure rather than content. It does not dictate how to think or make decisions for you. A common misconception is that logic serves as a rigid, emotionless guide to decision-making, a trope frequently misrepresented in creative media. The character of Spock from Star Trek epitomizes this view, portraying a being governed by the 'laws' of logic, leading to decisions that are seemingly devoid of emotion. However, this is a misrepresentation. Logic, in its essence, is not normative in this regard; it's about coherence rather than content.
Where logic can be considered normative is in its ability to determine which line of reasoning is coherent and which is not, hence my saying, "logic is the guardian of coherence." However, coherence alone is not a direct path to truth. It is possible to construct coherent arguments that lead to completely opposing conclusions. This observation shifts the perspective towards a descriptive understanding of logic. We examine reasoning to determine its coherence, not necessarily its truth or applicability.
Yet, describing logic as purely descriptive, akin to a scientist observing and predicting human thought patterns, also falls short. Human reasoning is complex, often illogical, riddled with biases, emotions, and inconsistencies. Logic is not a naturally occurring phenomenon to be observed.
So, where does this leave us in the normative versus descriptive debate? The dichotomy itself seems to be a false dilemma. It implies a necessity to choose one perspective over the other, yet neither fully encapsulates the essence of logic. That's why I advocate for a synthesis of both views: logic is both normative and descriptive.
To articulate this fusion, I use the phrase “logic is the description of the ideal.” Logicians don't merely describe how people think, akin to psychologists, but rather they model how ideal agents would reason, similar to how economists conceptualize the actions of ideal agents in hypothetical markets. This involves certain assumptions about what constitutes an ideal reasoner. Part of my work, particularly in 'Logic in the Wild,' focuses on reconciling these idealized concepts with real-world reasoning.
Studying these ideal situations is akin to how scientists construct mathematical models: they describe laws operating under controlled, ideal conditions. Therefore, describing the ideal becomes normative, setting a benchmark for evaluating real reasoning. By comparing actual reasoning to this ideal standard, logic begins to guide and inform our thought processes.
In conclusion, logic straddles the line between being normative and descriptive. It is normative because it outlines ideal reasoning, yet it is also descriptive as it explores the structures and patterns of thought. Embracing this duality offers a more comprehensive understanding of logic, moving beyond the confines of choosing one aspect over the other. Logic, in essence, is normative because it describes the ideal.
