Except in unusual cases where the entire class is known, deductive reasoning depends on prior induction. This means that all reasoning from the senses has a circular nature. From induction the properties of the class are surmised by examining a statistically useful subset of the class. Once the properties of the class are known it is possible to begin deductive reasoning, saying all who have B are an A, C has a B, so C must be an A.
The dependence of deduction on prior induction hasn’t been recognized, meaning that men are convinced deduction is an absolute process. Instead they’re just beginning with premises that no one questions, where the induction seems obvious or intuitive. It isn’t as important in natural science, where for instance the species are reliably identified by their traits. However it is critical when the mind turns to metaphysics, because the inner properties of the people of Earth are not known or understood, and cannot be sampled.
Take the example ubiquitous in logic textbooks, All men are mortal, Socrates is a man, therefore Socrates is mortal. Instead put “Jesus” in the sentence. Then you find Christians disagreeing that Jesus was a man, saying He was an immortal God instead. You can say, All bodies are mortal, Socrates had a body, therefore Socrates’ body was mortal. But if Socrates like Jesus was aware of Himself as having eternal spirit above the body, the original syllogism is seen to be a remark made by people who were ignorant about spirit.
In general a serious flaw in human intelligence is to make the presumption something has been known, when it has only been categorized. Placing things into categories is a means by which we simplify our interactions with the world, but the categories must be versatile and the assignations accurate. Men deduce too much, in other words, when more induction was required to fully understand the situation. There’s also the question of the goodness of the categories, as it might be shown, for instance, sinful minds have sinful categories. One may say those making war have categories incompatible with friendship.
The Christians would certainly say the Pharisees categorized Jesus wrongly, but are they categorizing Him rightly? The further question arises of the mind’s capacities, whether some things might be impossible to think, for instance to understand when one is in the Presence of the Deity, embodied. Christians say Jesus was a “rebel,” that He would challenge them and even make them uncomfortable, but from my perspective these are only the “Neo-Pharisees,” prepared to persecute the Lord if He gets in the way of desire. The lessons from the Pharisees do not penetrate, when wisdom always looks unfavorable.
