Quotes & Sayings About Deductive Reasoning

Theologians, and religionists in general, start with a fantasy premise and then proceed to apply rigorous formal logic to tease out its implications. Stark himself points out that "theology consists of formal reasoning about God." This is admirably exact. Theologians, beginning with a wished-for creation of their own minds, analyze that creation's characteristics by rigorous application of the principles of formal - that is, deductive - logic. — Andrew Bernstein

The word 'proof' should strictly only be used when we are dealing with deductive inferences.... Popper claimed that scientists only need to use deductive inferences.... So if a scientist is only interested in demonstrating that a given theory is false, she may be able to accomplish her goal without the use of inductive inferences.... When a scientist collects experimental data, her aim might be to show that a particular theory...is false. She will have to resort to inductive reasoning.... So Popper's attempt to show that science can get by without induction does not succeed. — Samir Okasha

No discussion of logic is complete without a refresher course in the difference between inductive and deductive reasoning. By its strictest definition, inductive reasoning proves a general principle - your idea worth spreading - by highlighting a group of specific events, trends, or observations. In contrast, deductive reasoning builds up to a specific principle - again, your idea worth spreading - through a chain of increasingly narrow statements. — Jeremey Donovan

You often show yourself without any faculty of deductive reasoning. — Rafael Sabatini

Your powers of deductive reasoning are stunning," spits Tobias. "Consider me awed. — Veronica Roth

Inferences of Science and Common Sense differ from those of deductive logic and mathematics in a very important respect, namely, when the premises are true and the reasoning correct, the conclusion is only probable. — Bertrand Russell

You should carefully study the Art of Reasoning, as it is what most people are very deficient in, and I know few things more disagreeable than to argue, or even converse with a man who has no idea of inductive and deductive philosophy. — William John Wills

If I sound as if I'm always predicting ominous things, it's because I'm a pragmatist. I use deductive reasoning to generalize, and I suppose this sometimes ends up sounding like unlucky prophecies. You know why? Because reality's just the accumulation of ominous prophecies come to life. You have to only open a newspaper on any given day and weigh the good news versus the bad, and you'll see what I mean. — Haruki Murakami

The discovery of geometry had intoxicated them, and its a priori deductive method appeared capable of universal application. They would prove, for instance, that all reality is one, that there is no such thing as change, that the world of sense is a world of mere illusion; and the strangeness of their results gave them no qualms because they believed in the correctness of their reasoning. — Bertrand Russell

It was a good answer that was made by one who when they showed him hanging in a temple a picture of those who had paid their vows as having escaped shipwreck, and would have him say whether he did not now acknowledge the power of the gods, - 'Aye,' asked he again, 'but where are they painted that were drowned after their vows?' And such is the way of all superstition, whether in astrology, dreams, omens, divine judgments, or the like; wherein men, having a delight in such vanities, mark the events where they are fulfilled, but where they fail, though this happens much oftener, neglect and pass them by. — Francis Bacon

Our society's almost doctrinal emphasis upon deductive reasoning, convergent thinking and selective retention perversely excludes divergent thinking, approximation and, importantly, guessing. If we are truly to understand the adolescent mind and develop effective ways to minimize the effects of risk-taking behaviour, we really need to understand these processes and engage with them. There is no logic involved with drug-taking and gambling. Adults can learn, too; understanding these mechanisms will also allow us to encourage creativity and value the spontaneity so characteristic of the adolescent mind. — Tony Little

Mathematics, in its widest significance, is the development of all types of formal, necessary, deductive reasoning. — Alfred North Whitehead

Some things cannot be perceived with the five senses; they can only be conceived by the Holy Spirit. Some things cannot be deduced via deductive reasoning; they can only be imagined by the Holy Spirit. Some things cannot be learned by logic; they can only be revealed by the Holy Spirit. — Mark Batterson

I start with an image, then I go from the image toward exploring the situation. Then I write a scene, and from the scene I find the character, from the character I find the larger plot. It's like deductive reasoning - I start with the smaller stuff and work backward. — Dan Chaon