A chief element in this modernness of Locke was something that had hardly appeared before in pure philosophy, although common in religion: I mean, the tendency to deny one's own presuppositions--not by accident or inadvertently, but proudly and with an air of triumph. Presuppositions are imposed on all of us by life itself: for instance the presupposition that life is to continue, and that it is worth living. Belief is born on the wing and awakes to many tacit commitments. Afterwards, in reflection, we may wonder at finding these presuppositions on our hands and, being ignorant of the natural causes which have imposed them on the animal mind, we may be offended at them. Their arbitrary and dogmatic character will tempt us to condemn them, and to take for granted that the analysis which undermines them is justified, and will prove fruitful. But this critical assurance in its turn seems to rely on a dubious presupposition, namely, that human opinion must always evolve in a single line, dialectically, providentially, and irresistibly. It is at least conceivable that the opposite should sometimes be the case. Some of the primitive presuppositions of human reason might have been correct and inevitable, whilst the tendency to deny them might have sprung from a plausible misunderstanding, or the exaggeration of a half-truth: so that the critical opinion itself, after destroying the spontaneous assumptions on which it rested, might be incapable of subsisting. In Locke the central presuppositions, which he embraced heartily and without question, were those of common sense. He adopted what he calls a "plain, historical method", fit, in his own words, "to be brought into well-bred company and polite conversation". Men, "barely by the use of their natural faculties", might attain to all the knowledge possible or worth having. All children, he writes, "that are born into this world, being surrounded with bodies that perpetually and diversely affect them" have "a variety of ideas imprinted" on their minds. "External material things as objects of Sensation, and the operations of our own minds as objects of Reflection, are to me", he continues, "the only originals from which all our ideas take their beginnings." "Every act of sensation", he writes elsewhere, "when duly considered, gives us an equal view of both parts of nature, the corporeal and the spiritual. For whilst I know, by seeing or hearing,... that there is some corporeal being without me, the object of that sensation, I do more certainly know that there is some spiritual being within me that sees and hears."