But suppose we are permitted to employ the term "nature" to denote the essential properties of matter, and the various forms of energy,[247] potential and kinetic; and suppose we admit that matter is indestructible, and that the amount of energy in the world is unchanged, the sum of the actual and potential energies being a constant quantity; still we are not entitled from these premises to infer the absolute uniformity in the succession of events--that is, the uniformity of the phenomenal. We have already seen that no phenomenon known to man is the result of a single property of matter or a single form of energy. "All issues in nature are the effects produced upon matter by the resultant of component forces." The phenomena of nature are the result of adjustments, combinations, and distributions of matter and of force in endless variety and complexity. Hence we have in nature the variable, the contingent, the particular, as well as the invariable, the uniform, and the general. This is admitted by Comte: "That which engenders this _irregular variability_ of the effect is the great number of different agents determining at the same time the same phenomena; and from which it results, in the most complicated phenomena, _that there are no two cases precisely alike_. We have no occasion, in order to find such complexity, to go to the phenomena of living beings. It presents itself in bodies without life, for example, in studying meteorological phenomena.... _Their multiplicity renders the effects as irregularly variable as if every cause had not been subject to any precise condition._"[248]