hume

There is no necessity that a generous action barely mentioned
in an old history or remote gazette should communicate
any strong feelings of applause and admiration.
Virtue, placed at such a distance, is like a fixed star,
which though to the eye of reason it may appear as luminous as the sun in his meridian,
is so infinitely removed as to affect the senses, neither with light nor heat.
Bring this virtue nearer, by our acquiantance or connexion with the persons,
... our hearts are immediately caught, our sympathy enlivened,
and our cool approbation converted into the warmest sentiments...
These principles of humanity and sympathy enter so deeply into all our sentiments,
and have so powerful an influence, as may enable them to excite the strongest censure and applause.

Primary Sources:
An Enquiry Concerning Human Understanding (1748) (Selby-Bigge ed)
A Treatise of Human Nature Books 1-2 (1739); 3 (1740)(Selby-Bigge)
Essays: Moral, Political and Literary Vol 1 (1741); Vol 2 (1742) (Green and Gross ed)
Political Essays (1752) (Hendel ed)
A Letter from a Gentlemen to His Friend in Edinburgh
The Letters of David Hume 2 Vols (Greig ed)
New Letters of David Hume (Klibansky ed)
Dialogues Concerning Natural Religion (1779) (Norman Kemp Smith ed)
Dialogues Concerning Natural Religion & The Immortality of the Soul and Suicide (Popkin ed)
An Inquiry Concerning the Principles of Morals (1751) (Hendel ed)
Four Dissertations (1757):
1. The Natural History of Religion
2. Of the Passions
3. Of Tragedy
4. Of the Standard of Taste

Secondary Sources:
E.C. Mossner: The Life of David Hume
D. Broiles: The Moral Philosophy of David Hume
A. Flew: Hume's Philosophy of Belief: A Study of His First Inquiry
A.B. Glanthe: Hume's Theory of the Passions and Morals
R. Kydd: Reason and Conduct in Hume's Treatise
N. K. Smith: The Philosophy of David Hume
G.E. Moore: Hume's Philosophy
Thomas Reid: Essays on the Intellectual Powers of Man (Essay 2)
Richard Price: A Review of the Principal Questions of Morals