None but those who have ...

None but those who have learned the art of subjecting their senses as well as reason to hypothetical systems can be persuaded by the most specious rhetorician that the lots of life are equal; yet it cannot be denied that every one has his peculiar pleasures and vexations, that external accidents operate variously upon different minds, and that no man can exactly judge from his own sensations what another would feel in the same circumstances.
None but those who have learned the art of subjecting their senses as well as reason to hypothetical systems can be persuaded by the most specious rhetorician that the lots of life are equal; yet it cannot be denied that every one has his peculiar pleasures and vexations, that external accidents operate variously upon different minds, and that no man can exactly judge from his own sensations what another would feel in the same circumstances.

Quotes from the same author

If a man does not make new acquaintances as he advances through life, he will soon find himself left alone. A man, sir, should keep his friendship in a constant repair.
To keep your secret is wisdom; but to expect others to keep it is folly.
Love is the wisdom of the fool and the folly of the wise.
Memory is the mother of all wisdom.
Friendship, like love, is destroyed by long absence, though it may be increased by short intermissions.