Those who are accustomed to judge by feeling do not understand the process of reasoning, for they would understand at first sight, and are not used to seek for principles. And others, on the contrary, who are accustomed to reason from principles, do not at all understand matters of feeling, seeking principles, and being unable to see at a glance.

It requires a very unusual mind to undertake the analysis of the obvious.

Great intellects are skeptical.

Those who are not shocked when they first come across quantum theory cannot possibly have understood it.

People in this world look at things mistakenly, and think that what they do not understand must be the void. This is not the true void. It is bewilderment.

The mind leans on [innate] principles every moment, but it does not come so easily to distinguish them and to represent them distinctly and separately, because that demands great attention to its acts, and the majority of people, little accustomed to think, has little of it.

people often confuse complex ideas that cannot be simplified into a media-friendly statement as symptomatic of a confused mind.

they are mystified by certain instances.

It is not a very pleasing spectacle to observe uncultivated ignorance and crudity of mind, with neither form nor taste, without the capacity to concentrate its thoughts on an abstract proposition, still less on a connected statement of such propositions, confidently proclaiming itself to be intellectual freedom and

So blind is the curiosity by which mortals are possessed, that they often conduct their minds along unexplored routes, having no reason to hope for success, but merely being willing to risk the experiment of finding whether the truth they seek lies there.

The dull mind, once arriving at an inference that flatters the desire, is rarely able to retain the impression that the notion from which the inference started was purely problematic.

They were presented in enigmas, clad in riddles, and taught by an wise men in the most mysterious way that could be devised, not because they contain some secret evil, or are contrary to the fundamental principles of the Law (as fools think who are only philosophers in their own eyes), but because of the incapacity of man to comprehend them at the beginning of his studies:

There are some ideas so absurd that only an intellectual could believe them.

...the incredulity of mankind, who do not truly believe in anything new until they have had actual experience of it.