It is difficult to speak of the universal specifically.

Sometimes it is more difficult to formulate the criterion for a problem than to state the question itself.

Despite these common properties, and the fundamental unity of life they reveal, it is difficult to make generalizations about living organisms.

Good cannot be a single and universal general notion; if it were, it would not be predictable in all the categories, but only in one.

If your private actions do not generalize, then you cannot have general ideas.

To apply general tools to specific problems is to fail.

There are very few things that can be proved rigorously in condensed matter physics.

While it is not hard to suggest improvements on common methods of design and construction, it is very hard to introduce them.

General laws cannot give way to particular cases.

From <nowiki>[</nowiki>Grothendieck<nowiki>]</nowiki> and his example, I have also learned not to take glory in the difficulty of a proof: difficulty means we have not understood. The ideal is to be able to paint a landscape in which the proof is obvious.

General ideas are no proof of the strength, but rather of the insufficiency of the human intellect.

Proof itself, of any sort, is impossible, without an axiom (as Gödel proved). Thus faith in God is a prerequisite for all proof.

For an induction, despite its formal generality, is always in its own value a particular judgment, always comes short of full universality; whereas, to establish the apriority of an element, we must show it to be strictly universal, or, in other words, necessary.

Equally possible cases do not always exist, e.g, they are not present in the game with a biased die, or in life insurance. Strictly speaking, the propositions of the classical theory are therefore no applicable to these cases.