ssics. Another important paper is his
"Classification of Loci" (1878). He also published several papers on
algebraic forms and projective geometry.

As a philosopher Clifford's name is chiefly associated with two phrases
of his coining, "mind-stuff" and the "tribal self." The former
symbolizes his metaphysical conception, which was suggested to him by
his reading of Spinoza. "Briefly put," says Sir F. Pollock, "the
conception is that mind is the one ultimate reality; not mind as we know
it in the complex forms of conscious feeling and thought, but the
simpler elements out of which thought and feeling are built up. The
hypothetical ultimate element of mind, or atom of mind-stuff, precisely
corresponds to the hypothetical atom of matter, being the ultimate fact
of which the material atom is the phenomenon. Matter and the sensible
universe are the relations between particular organisms, that is, mind
organized into consciousness, and the rest of the world. This leads to
results which would in a loose and popular sense be called materialist.
But the theory must, as a metaphysical theory, be reckoned on the
idealist side. To speak technically, it is an idealist monism." The
other phrase, "tribal self," gives the key to Clifford's ethical view,
which explains conscience and the moral law by the development in each
individual of a "self," which prescribes the conduct conducive to the
welfare of the "tribe." Much of Clifford's contemporary prominence was
due to his attitude towards religion. Animated by an intense love of
truth and devotion to public duty, he waged war on such ecclesiastical
systems as seemed to him to favour obscurantism, and to put the claims
of sect above those of human society. The alarm was greater, as theology
was still unreconciled with the Darwinian theory; and Clifford was
regarded as a dangerous champion of the anti-spiritual tendencies then
imputed to modern science.

His works, published wholly or in part since his death, are _Elements
of Dynamic_ (1879-1887); _Seeing and Thinking_, popular science
lectures (1879); _Lectures and Essays_, with an introduction by Sir F.
Pollock (1879); _Mathematical Papers_, edited by R. Tucker, with an
introduction by Henry J. S. Smith (1882); and _The Common Sense of the
Exact Sciences_, completed by Professor Karl Pearson (1885).

CLIFFORD OF CHUDLEIGH, THOMAS CLIFFORD, 1ST BARON (1630-1673), English
lord treasurer, a member of the ancient famil