But that deficient agreeableness in social life with which men of genius have been often reproached, may really result from the nature of those qualities which conduce to the greatness of their public character. A thinker whose mind is saturated with knowledge on a particular subject, will be apt to deliver himself authoritatively; but he will then pass for a dogmatist: should he hesitate, that he may correct an equivocal expression, or bring nearer a remote idea, he is in danger of sinking into pedantry or rising into genius. Even the fulness of knowledge has its tediousness. "It is rare," said MALEBRANCHE, "that those who meditate profoundly can explain well the objects they have meditated on; for they hesitate when they have to speak; they are scrupulous to convey false ideas or use inaccurate terms. They do not choose to speak, like others, merely for the sake of talking." A vivid and sudden perception of truth, or a severe scrutiny after it, may elevate the voice, and burst with an irruptive heat on the subdued tone of conversation. These men are too much in earnest for the weak or the vain. Such seriousness kills their feeble animal spirits. SMEATON, a creative genius of his class, had a warmth of expression which seemed repulsive to many: it arose from an intense application of mind, which impelled him to break out hastily when anything was said that did not accord with his ideas. Persons who are obstinate till they can give up their notions with a safe conscience, are troublesome intimates. Often too the cold tardiness of decision is only the strict balancing of scepticism or candour, while obscurity as frequently may arise from the deficiency of previous knowledge in the listener. It was said that NEWTON in conversation did not seem to understand his own writings, and it was supposed that his memory had decayed. The fact, however, was not so; and Pemberton makes a curious distinction, which accounts for Newton _not always being ready to speak_ on subjects of which he was the sole master. "Inventors seem to treasure up in their own minds what they have found out, after another manner than those do the same things that have not this inventive faculty. The former, when they have occasion to produce their knowledge, in some means are obliged immediately to investigate part of what they want. For this they are not equally fit at all times; and thus it has often happened, that such as retain things chiefly by means of a very strong memory, have appeared off-hand more expert than the discoverers themselves."