There is nothing in the understanding which has not come from the senses, except the understanding itself, or the one who understands.

A man shouldn’t claim to know even himself as he really is by knowing himself through inner sensation — i.e. by introspection. For since he doesn’t produce himself (so to speak) or get his concept of himself a priori but only empirically, it is natural that he gets his knowledge of himself through inner sense and consequently only through how his nature appears and how his consciousness is affected. But beyond the character of his own subject, which is made up out of these mere appearances, he necessarily assumes something else underlying it, namely his I as it is in itself. Thus in respect to mere perception and receptivity to sensations he must count himself as belonging to the sensible world; but in respect to whatever pure activity there may be in himself (which reaches his consciousness directly and not by affecting the inner or outer senses) he must count himself as belonging to the intellectual world — though he doesn’t know anything more about it.

To understand anything is to find in it something which is our own.

We can only make sense of ourselves in relation to someone or something. To be a person, we must be recognized as a person.

You can only understand people if you feel them in yourself.

I am unable, when I turn to myself, to recognize any of my faculties or my capacities. The inner sensation which I have of myself informs me that I am, that I think, that I will, that I have sensory awareness, that I suffer, and so on; but it provides me with no knowledge whatever of what I am — of the nature of my thought, my sensations, my passions, or my pain — or the mutual relations that obtain between all these things … I have no idea whatever of my soul.

feel what I feel within myself — that is trying to become aware of it also what I feel in others not being ashamed of my feeling, thoughts — or ideas realize the thing that they are —

I say that it is possible to have some knowledge without the help of the senses. For in the Divine Mind all knowledge exists from eternity, and not only is there in it certain knowledge of universals but also of all singulars. ...Similarly, intelligence receiving irradiation from the primary light see all knowable things, both universal and singulars, in the primary light itself. Moreover, the Divine Mind, in the reflection of its intelligence upon Itself, knows the very things which come after Itself, because it is itself their cause. Therefore, those who are without any senses have true knowledge.

You imagine that what you can't understand is either spiritual or does not exist. The conclusion is quite wrong; rather there are obviously a million things in the universe that we would need a million quite different organs to understand. For example, I perceive by my senses what makes a magnet point north, what makes tides rise and fall, and what becomes of an animal after death. Your people are not proportioned to perceive such miracles, just as someone blind from birth cannot imagine the beauty of a landscape, the colors of a painting or the shadings of an iris. He will imagine them as something palpable, edible, audible or olfactory. Likewise, if I were to explain to you what I perceive by the senses you do not have, you would interpret it as something that could be heard, seen, touched, smelled or tasted; but it is not like that.

No being knows. He thinks he knows. A few grams strategically shifted here and there in his organism, and he knows, or thinks he knows, something altogether otherwise. All is attitude and relativity.

To have real knowledge, one must understand the essence of things and not only their manifestations.

Knowledge is employed in the service of the necessity of life and primarily in the service of the instinct of personal preservation. The necessity and this instinct have created in man the organs of knowledge and given them such capacity as they possess. Man sees, hears, touches, tastes and smells that which it is necessary for him to see, hear, touch, taste and smell in order to preserve his life. The decay or loss of any of these senses increases the risks with which his life is environed, and if it increases them less in the state of society in which we are actually living, the reason is that some see, hear, touch, taste and smell for others. A blind man, by himself and without a guide, could not live long. Society is an additional sense; it is the true common sense.

In order to understand, observe, deduce, man must first be conscious of himself as alive.

Nothing is in the intellect that was not first in the senses, except the intellect itself.