Logic in Action: From Ancient Theories to Modern Debates
What are examples of logic in use?
Answering this isn't straightforward. It depends on whether you mean a clear example of someone using logic to make a decision or to arrive at truth. I'm not even sure such an example exists, as that's not primarily what logic is useful for. Instead, I prefer to illustrate how logic operates. One aspect is that logic allows us to seek coherence beyond mere truth. Though I'm no expert, I enjoy exploring ancient science and seeing how theorists used mathematics to frame their theories, explain the world, and make predictions—just as we do today. Yet, many of these theories are false. Consider optics, for example. Ptolemy believed that visual rays emanated from the eyes, scanning the world around us. He thought of sight as similar to touch, or how a visually impaired person might use a walking stick to navigate. While Ptolemy was incorrect—there are no visual rays—he wasn’t foolish. His theories were coherent, and it’s fascinating to see how much mathematics he and other ancient scientists developed, including theories about mirrors and image distortion.
Isaac Newton developed a universal theory of gravity that we still teach and use today to build bridges and send people into space, yet his theory is technically false, replaced by Einstein's theory of gravity. Despite long debates about the fundamental assumptions Newton made, the coherence of his theory helped it survive the test of time and remain a pillar of modern science.
In everyday life, a similar appreciation for logic can help us understand others' views without fixating on the absolute truth of their statements. It takes a measure of humility to refrain from challenging the truths in their ideas and instead seek coherence in their views as a source of learning.
Another example of appreciating logic can be seen in debates over controversial issues, such as the ongoing discussion about equity between male and female players in tennis. Historically, men have earned more than women in grand slam tournaments because they play best of five sets, while women play best of three. This disparity was defended by the slogan “equal pay for equal play,” suggesting that as long as women played shorter matches, they shouldn’t receive equal prize money. In practice, however, achieving this is impractical—not because of any supposed inability of women to play longer matches, but because the two-week duration of tournaments does not allow time for everyone to play best of five sets. A logical solution to achieve "equal play" would be to have men also play best of three sets, particularly if all players switched to best of five only for the semi-finals and finals. The logical flaw in the original argument is that it actually undermines the case against equal pay and aligns more logically with rectifying the pay gap by ensuring that everyone plays the same number of sets and receives equal pay. While the intention behind the slogan is to preserve the status quo, a logical resolution offers an opposite solution.
