Nevertheless, while many similar hindrances to human action exist, such as the friction-hindrance to perpetual motion, and the wall which kept Pyramus from Thisbe, yet, on the whole, most of the so-called external restraints are far less serious barriers to freedom than we realize. This is not only attested by the magnificent conquests of nature recently made by applied science, but it might also be deduced from the properties of man’s protoplasm as modified in his muscular architecture. For protoplasm is liquid, and liquids flow; and man’s stream of thought as a derivative of his liquid protoplasm acquires its labile character as a sort of natural right. Just as a liquid under pressure transmits that pressure in all directions, so a man who is made of good protoplasm tends, when confronted by such obstacles as we have just described, to think, and plan, and experiment, that is, TO FLOW, out of the difficulty. His neuro-muscular equipment also singularly facilitates the turning of his wish into a will. Our muscles do not only contract and relax to produce lever movements in one plane, but they also combine their movements into pronation, supination, and rotation, and these synergic actions enable us to explore the obstacle and almost literally to flow around it. This is also the mechanism by which we puzzle out any problem. The all-or-none principle makes mental analysis always possible and often accurate. Applied to Pyramus, this means that the wall that separates him from Thisbe stimulates him with her aid so variously that he not only rebels and laments, but also starts to explore its surface and its possibilities, with the final result that he vaults it and descends “until he can come at Thisbe’s lips more directly.” There has always been an abundance of old saws to encourage the bold and the faint-hearted to regard obstacles as merely stepping-stones to future success, but the physiological basis of such maxims we are only beginning to comprehend. In fine, then, when we speak of a permanent obstacle to our actions, we mean it only in so far as we do not also imply some serious deficiency in the quality of our protoplasm. The relation between this second type of freedom and obligation is very obviously hinted at by the popular maxims on the theme of perseverance. Moreover, it is historically demonstrable that pragmatic urgency usually increases in direct ratio to the ease with which external restraints can be surmounted. On the other hand, it is gradually becoming recognized that “there are hundreds of thousands of human beings who can by no possibility ever do what is expected of them by society. Society must give over expecting such things.”[22] Those who have no power to plan, scheme, or supervise, are consequently not educated enough to appreciate the obligations which such abilities involve.