occasions, is the mind forced on to pronounce,
without sufficient data for pronouncing. Who does not form some view or
other, for instance, of any public man, or any public event, nay, even so
far in some cases as to reach the mental delineation of his appearance or
of its scene? yet how few have a right to form any view. Hence the
misconceptions of character, hence the false impressions and reports of
words or deeds, which are the rule, rather than the exception, in the
world at large; hence the extravagances of undisciplined talent, and the
narrowness of conceited ignorance; because, though it is no easy matter to
view things correctly, nevertheless the busy mind will ever be viewing. We
cannot do without a view, and we put up with an illusion, when we cannot
get a truth.

4.

Now, observe how this impatience acts in matters of research and
speculation. What happens to the ignorant and hotheaded, will take place
in the case of every person whose education or pursuits are contracted,
whether they be merely professional, merely scientific, or of whatever
other peculiar complexion. Men, whose life lies in the cultivation of one
science, or the exercise of one method of thought, have no more right,
though they have often more ambition, to generalize upon the basis of
their own pursuit but beyond its range, than the schoolboy or the
ploughman to judge of a Prime Minister. But they must have something to
say on every subject; habit, fashion, the public require it of them: and,
if so, they can only give sentence according to their knowledge. You might
think this ought to make such a person modest in his enunciations; not so:
too often it happens that, in proportion to the narrowness of his
knowledge, is, not his distrust of it, but the deep hold it has upon him,
his absolute conviction of his own conclusions, and his positiveness in
maintaining them. He has the obstinacy of the bigot, whom he scorns,
without the bigot's apology, that he has been taught, as he thinks, his
doctrine from heaven. Thus he becomes, what is commonly called, a man of
one idea; which properly means a man of one science, and of the view,
partly true, but subordinate, partly false, which is all that can proceed
out of any thing so partial. Hence it is that we have the principles of
utility, of combination, of progress, of philanthropy, or, in material
sciences, comparative anatomy, phrenology, electricity, exalted into
leading ideas, and keys,