{Irradiation}

The process of thought, at this point, may be thus roughly sketched: – I say to myself – »Unity, as I have explained it, is a truth – I feel it. Diffusion is a truth – I see it. Irradiation, by which alone these two truths are reconciled, is a consequent truth – I perceive it. Equability of diffusion, first deduced à priori and then corroborated by the inspection of phænomena, is also a truth – I fully admit it. So far all is clear around me: – there are no clouds behind which the secret – the great secret of the gravitating modus operandi – can possibly lie hidden; – but this secret lies hereabouts, most assuredly; and were there but a cloud in view, I should be driven to suspicion of that cloud.« And now, just as I say this, there actually comes a cloud into view. This cloud is the seeming impossibility of reconciling my truth, irradiation, with my truth, equability of diffusion. I say now: – »Behind this seeming impossibility is to be found what I desire.« I do not say »real impossibility;« for invincible faith in my truths assures me that it is a mere difficulty after all – but I go on to say, with unflinching confidence, that, when this difficulty shall be solved, we shall find, wrapped up in the process of solution, the key to the secret at which we aim. Moreover – I feel that we shall discover but one possible solution of the difficulty; this for the reason that, were there two, one would be supererogatory – would be fruitless – would be empty – would contain no key – since no duplicate key can be needed to any secret of Nature.

And now, let us see: – Our usual notions of irradiation – in fact all our distinct notions of it – are caught merely from the process as we see it exemplified in Light. Here there is a continuous outpouring of ray-streams, and with a force which we have at least no right to suppose varies at all. Now, in any such irradiation as this – continuous and of unvarying force – the regions nearer the centre must inevitably be always more crowded with the irradiated matter than the regions more remote. But I have assumed no such irradiation as this. I assumed no continuous irradiation; and for the simple reason that such an assumption would have involved, first, the necessity of entertaining a conception which I have shown no man can entertain, and which (as I will more fully explain hereafter) all observation of the firmament refutes – the conception of the absolute infinity of the Universe of stars – and would have involved, secondly, the impossibility of understanding a rëaction – that is, gravitation – as existing now – since, while an act is continued, no rëaction, of course, can take place. My assumption, then, or rather my inevitable deduction from just premises – was that of a determinate irradiation – one finally discontinued.