Aristotle, the model scientist, the man of cool head and detached observation, unbiased, impersonal, does not display any dispassionate aloofness in his consideration of reason. He so loves it and delights in it that when it is the theme of discourse he cannot be held within the sober bounds of the scientific spirit. His words must be quoted, they are so characteristically Greek: Since then reason is divine in comparison with man’s whole nature, the life according to reason must be divine in comparison with (usual) human life. Nor ought we to pay regard to those who exhort us that as men we ought to think human things and keep our eyes upon mortality: nay, as far as may be, we should endeavor to rise to that which is immortal, and live in conformity with that which is best, in us. Now, what is characteristic of any nature is that which is best for it and gives most joy. Such to man is the life according to reason, since it is this that makes him man.

In his well-known statement in the Poetics that poetry has a higher truth than history since it expresses truth of general application whereas that of history is partial and limited, he is not speaking as a scientist nor would the statement commend itself to the scientific mind outside of Greece. There is no evidence, again, of the scientist’s point of view in the great passage where he sets forth the reason for the work of his life, his search into the nature of all living things: The glory, doubtless, of the heavenly bodies fills us with more delight than the contemplation of these lowly things, but the heavens are high and far off, and the knowledge of celestial things that our senses give us, is scanty and dim. Living creatures, on the contrary, are at our door, and if we so desire we may gain full and certain knowledge of each and all. We take pleasure in a statue’s beauty; should not then the living fill us with delight? And all the more if in the spirit of the love of knowledge we search for causes and bring to light evidences of meaning. Then will nature’s purpose and her deep-seated laws be revealed in all things, all tending in her multitudinous work to one form or another of the beautiful. Did ever scientist outside of Greece so state the object of scientific research? To Aristotle, being a Greek, it was apparent that the full purpose of that high enterprise could not be expressed in any way except the way of poetry, and, being a Greek, he was able so to express it. Spirituality inevitably brings to our mind

You could give Aristotle a tutorial. And you could thrill him to the core of his being. Aristotle was an encyclopedic polymath, an all time intellect. Yet not only can you know more than him about the world, you also can have a deeper understanding of how everything works. Such is the privilege of living after Newton, Darwin, Einstein, Planck, Watson, Crick and their colleagues.

Reason in man is rather like God in the world.

Aristotle was famous for knowing everything. He taught that the brain exists merely to cool the blood and is not involved in the process of thinking. This is true only of certain persons.

Man is conscious of a universal soul within or behind his individual life, wherein, as in a firmament, the natures of Justice, Truth, Love, Freedom, arise and shine. This universal soul, he calls Reason: it is not mine, or thine, or his, but we are its; we are its property and men. And the blue sky in which the private earth is buried, the sky with its eternal calm, and full of everlasting orbs, is the type of Reason. That which, intellectually considered, we call Reason, considered in relation to nature, we call Spirit. Spirit is the Creator. Spirit hath life in itself. And man in all ages and countries, embodies it in his language, as the FATHER.

Perhaps I am a crank, Martin. There are many who hate me. There are plots against me—oh, you t'ink I imagine it, but you shall see! I make many mistakes. But one thing I keep always pure: the religion of a scientist. To be a scientist—it is not just a different job, so that a man should choose between being a scientist and being an explorer or a bond-salesman or a physician or a king or a farmer. It is a tangle of ver-y obscure emotions, like mysticism, or wanting to write poetry; it makes its victim all different from the good normal man. The normal man, he does not care much what he does except that he should eat and sleep and make love. But the scientist is intensely religious—he is so religious that he will not accept quarter-truths, because they are an insult to his faith. He wants that everything should be subject to inexorable laws. He is equal opposed to the capitalists who t'ink their silly money-grabbing is a system, and to liberals who t'ink man is not a fighting animal; he takes both the American booster and the European aristocrat, and he ignores all their blithering. Ignores it! All of it! He hates the preachers who talk their fables, but he iss not too kindly to the anthropologists and historians who can only make guesses, yet they have the nerf to call themselves scientists! Oh, yes, he is a man that all nice good-natured people should naturally hate! ~ Gottlieb, Ch. 26

Reason is to the philosopher what grace is to the Christian.
Grace causes the Christian to act, reason the philosopher. Other men are carried away by their passions, their actions not being preceded by reflection: these are the men who walk in darkness. On the other hand, the philosopher, even in his passions, acts only after reflection; he walks in the dark, but by a torch. The philosopher forms his principles from an infinity of particular observations. Most people adopt principles without thinking of the observations that have produced them, they believe the maxims exist, so to speak, by themselves. But the philosopher takes maxims from their source; he examines their origin; he knows their proper value, and he makes use of them only in so far as they suit him. Truth is not for the philosopher a mistress who corrupts his imagination and whom he believes to be found everywhere; he contents himself with being able to unravel it where he can perceive it. He does not confound it with probability; he takes for true what is true, for false what is false, for doubtful what is doubtful, and probable what is only probable. He does more, and here you have a great perfection of the philosopher: when he has no reason by which to judge, he knows how to live in suspension of judgment... The philosophical spirit is, then, a spirit of observation and exactness, which relates everything to true principles...

Aristotle’s thought is that to live well and flourishingly, a person needs to be educated—which means: informed, and able to think. He is of course right.

The dominant concept in Aristotle's philosophy of nature is his notion of causation. ...The final cause states that each substance has an inherent purpose. Thus there must be a purpose or design in the acorn such that it always grows into an oak tree. This aspect of existence is indicated by the word entelechy; this means the purpose that guides things to develop in one way rather than another.

In the knowledge of nature," Aristotle writes, the test of principles "is the unimpeachable evidence of the senses as to the fact." He holds that "lack of experience diminishes our power of taking a comprehensive view of the admitted facts. Hence those who dwell in the intimate association with nature and its phenomena grow more and more able to formulate, as the foundation of their theories, principles such as to admit of a wide and coherent development; while those whom devotion to abstract discussions has rendered unobservant of the facts are too ready to dogmatize on the basis of a few observations." Theories should be accredited, Aristotle insists, "only if what they affirm agrees with the facts.

Aristotle (De Anima, I. 1) makes in the first place the general remark that it appears as if the soul must, on the one hand, be regarded in its freedom as independent and as separable from the body, since in thinking it is independent; and, on the other hand, since in the emotions it appears to be united with the body and not separate, it must also be looked on as being inseparable from it; for the emotions show themselves as materialized Notions (λόγοι έννοια), as material modes of what is spiritual. With this a twofold method of considering the soul, also known to Aristotle, comes into play, namely the purely rational or logical view, on the one hand, and, on the other hand, the physical or physiological; these we still see practiced side by side. According to the one view, anger, for instance, is looked on as an eager desire for retaliation or the like; according to the other view it is the surging upward of the heartblood and the warm element in man. The former is the rational, the latter the material view of anger; just as one man may define a house as a shelter against wind, rain, and other destructive agencies, while another defines it as consisting of wood and stone; that is to say, the former gives the determination and the form, or the purpose of the thing, while the latter specifies the material it is made of, and its necessary conditions.

In fact, rationalism is to reason as scientism is to science.

In Aristotle the mind, regarded as the principle of life, divides into nutrition, sensation, and faculty of thought, corresponding to the inner most important stages in the succession of vital phenomena.