admitted. Before the shrine of truth, as discovered by facts and experience, the fairest theories and the most beautiful classifications must fall. The chemist of thirty years ago may be allowed to regret, that new discoveries in the science should disturb and confound his previous systems and arrangements; but he is not entitled to the rank of philosopher, if he does not give them up without a struggle, as soon as the experiments which refute them are fully established.
The same tendency to simplify and generalize, produces a still greater disinclination to allow of modifications, limitations, and exceptions to any rule or proposition, than to admit the operation of more causes than one. Nothing indeed is so unsatisfactory, and gives so unscientific and unmasterly an air to a proposition as to be obliged to make admissions of this kind; yet there is no truth of which I feel a stronger conviction than that there are many important propositions in political economy which absolutely require limitations and exceptions; and it may be confidently stated that the frequent combination of complicated causes, the action and reaction of cause and effect on each other, and the necessity of limitations and exceptions in a considerable number of important propositions, form the main difficulties of the science, and occasion those frequent mistakes which it must be allowed are made in the prediction of results.
To explain myself by an instance. Adam Smith has stated, that capitals are increased by parsimony, that every frugal man is a public benefactor,[1] and that the increase of wealth depends upon the balance of produce above consumption.[2] That these propositions are true to a great extent is perfectly unquestionable. No considerable and continued increase of wealth could possibly take place without that degree of frugality which occasions, annually, the conversion of some revenue into capital, and creates a balance of produce above consumption; but it is quite obvious
