TWO:In modern parlance, the word scepticism is often used to denote absolute unbelief. This, however, is a misapplication;124 and, properly speaking, it should be reserved, as it was by the Greeks, for those cases in which belief is simply withheld, or in which, as its etymology implies, the mental state connoted is a desire to consider of the matter before coming to a decision. But, of course, there are occasions when, either from prudence or politeness, absolute rejection of a proposition is veiled under the appearance of simple indecision or of a demand for further evidence; and at a time when to believe in certain theological dogmas was either dangerous or discreditable, the name sceptic may have been accepted on all hands as a convenient euphemism in speaking about persons who did not doubt, but denied them altogether. Again, taken in its original sense, the name sceptic is applicable to two entirely different, or rather diametrically opposite classes. The true philosopher is more slow to believe than other men, because he is better acquainted than they are with the rules of evidence, and with the apparently strong claims on our belief often possessed by propositions known to be false. To that extent, all philosophers are sceptics, and are rightly regarded as such by the vulgar; although their acceptance of many conclusions which the unlearned reject without examination, has the contrary effect of giving them a reputation for extraordinary credulity or even insanity. And this leads us to another aspect of scepticisman aspect under which, so far from being an element of philosophy, it is one of the most dangerous enemies that philosophy has to face. Instead of regarding the difficulties which beset the path of enquiry as a warning against premature conclusions, and a stimulus to more careful research, it is possible to make them a pretext for abandoning enquiry altogether. And it is also possible to regard the divergent answers given by different thinkers to the same problem, not as materials for comparison, selection or combination, nor even as indications of the various directions in which a solution is not to be sought, but as a proof that125 the problem altogether passes the power of human reason to solve.Judged upon theoretical grounds, and leaving out the mechanical conditions of operation, it would at once be conceded that a proper plan would be to move the lightest body; that is, if the tools and their attachments were heavier than the material to be acted upon, then the material should be moved for the cutting action, and vice versa. But in practice there are other conditions to be considered more important than a question of the relative weight of reciprocating parts; and it must be remembered that in solving any problem pertaining to machine action, the conditions of operation are to be considered first and have precedence over problems of strain, arrangement, or even the general principles of construction; that is, the conditions of operating must form a base from which proportions, arrangements, and so on, must be deduced. A standard planing machine, such as is employed for most kinds of work, is arranged with a running platen or carriage upon which the material is fastened and traversed beneath the cutting tools. [130] The uniformity of arrangement and design in machines of this kind in all countries wherever they are made, must lead to the conclusion that there are substantial reasons for employing running platens instead of giving a cutting movement to the tools.
