e _Essay on the
Human Understanding_ was the author also of the _Treatise on
Government_ and the _Letters on Toleration_. Hume, in those _Essays on
Trade and Politics_, which are free from the stain of infidelity,
was one of the most solid of thinkers; and he who produced the _Theory
of Moral Sentiments_ continues to give law at the present time, in his
_Wealth of Nations_, to the commerce of the civilised world. From a
subtile but comparatively narrow class of intellects, though
distinguished in the metaphysical province, mankind has received
much less. Berkeley was one of these, and may be regarded as their
type and representative. Save his metaphysics,--demonstrative of
the non-existence of matter, or demonstrative rather that fire is
not conscious of heat, nor ice of cold, nor yet our enlightened
surface of colour,--he bequeathed little else to the world than
his tar-water; and his tar-water, no longer recognised as a
universal medicine, has had its day, and is forgotten. Without
professing to know aught of German metaphysicians--for in the times
when we used to read Hume and Reid they were but little known in
this country--we can by no means rate them so high as the men whose
writings they are supplanting. What, we have been accustomed to ask,
are their trophies in the practical? Have any of them given to the
world even tar-water? Where are their Lockes, Humes, and Adam Smiths?
The man who, according to Johnson, can walk vigorously towards the
east, can walk vigorously toward the west also. How is it that these
German metaphysicians exhibit their vigour exclusively in walking one
way? Where are their works of a practical character, powerful enough
to give law to the species? Where their treatises like those of Locke
on _Toleration_ or on _Government_, or their essays like that of
Hume or of Adam Smith on the _Balance of Power_ or the _Wealth of
Nations_? Are they doing other, to use a very old illustration, than
merely milking rams, leaving their admirers and followers to hold
the pail?

Dugald Stewart, though mayhap less an original in the domain of
abstract thought than some of his predecessors, belongs emphatically
to the practical school. With him philosophy is simply common sense on
that large scale which renders it one of the least common things in
the world. And never, perhaps, was there a more thoroughly honest
seeker after truth. Burns somewhat whimsically describes him, in a
recently recovered letter gi