In considering it I shall faithfully adhere to the method I have hitherto followed, and shall support myself by presupposing all that has already been advanced. There is, indeed, just one thought which forms the content of this whole work. I have endeavoured to work it out in all other spheres, and I shall now do so with regard to human action. I shall then have done all that is in my power to communicate it as fully as possible.
Orain arteko kontsiderazio-erarekiko leial iraungo dut, eta orain arte suposiziotzat proposatutakoan oinarrituko naiz, are idazki oso honen edukia den pentsamendu bakarrean, orain arte gainerako objektu guztietan bezala gizakiaren egintzari dagokionez garatuko du, eta horrenbestez, ahal dudan heinean, azken ahalegina egingo dut ahalik eta erarik perfektuenean jakinarazteko.