other attribute, matter, it must be immaterial, something of the same nature as consciousness, only not conscious on the lower stages of existence. It seems to account for all movement and thought in the world.
Now that we have become acquainted with Haeckel's fundamental principles, let us observe what application is made of them. We shall take up in order the inorganic world, organic nature and psychic life.
The substance fills infinite space as a continuum. It is endowed with a mechanical form of activity, with a striving (Streben) to become dense or to contract. In this way little centers are formed of the parts of the universal substance which Haeckel calls pyknatoms, and which possess sensation (Empfindung) and impulse or striving (Streben), will-movements of the simplest kind, and hence are in a certain sense animated.[1] The atoms are not dead mass particles, but living elemental particles, endowed with the power of attraction and repulsion; love and hate are merely different expressions for this power of attraction and repulsion,[2] These original atoms are probably of the same size and essence, but they are not divisible. Their form is most likely spherical; they are inert (in the sense of physics), unchangeable, inelastic, not penetrable by ether. They have another quality, chemical affinity, an inclination to combine and to form little groups in a uniform way. These fixed groups of original atoms are the so-called elemental atoms, the known indecomposable atoms of chemistry. Hence the qualitative differences of our chemical elements are conditioned solely by the different number and configuration of the homogeneous original atoms. We do not know what is the nature of these original atoms themselves; perhaps it is prothyl.[3]
These atoms do not float in empty space, but in a continuous extremely thin intervening substance which represents the non-contracted part of the original substance. In this way the substance, which in its original state of rest has the same density throughout, differentiates into two parts: the pyknatoms, ponderable matter, and the intervening ether, the imponderable matter. The result of this separation or differentiation is a constant struggle between these antagonistic parts of substance, and to this struggle all physical processes are due. As was said before, these atoms are not dead and movable by external forces only; they possess sensation and will (in the lowest degrees, of course), they experience pleasure in the process of contraction (Verdichtung), pain in the process of tension (Spannung); they strive after the first and struggle against the last. Hence atoms are endowed with a universal 'soul' of the most primitive kind. The
