As a contrast to this, it was necessary, for the purposes of a critical work upon Anarchism, to go right back to its sources and to the writings of those who represented it. But here I found a further difficulty, which could not always be overcome. Where was I to get these writings? Our great public libraries, whose pride it is to possess the most complete collections possible of all the texts of Herodotus or Sophocles, have of course thought it beneath their dignity to place on their shelves the works of Anarchist doctrinaires, or even to collect the pamphlet literature for or against Anarchism--productions which certainly cannot take a very high rank from the point of view either of literature or of fact. The consequence of this foresight on the part of our librarians is that, to-day, anyone who inquires into the development of the social question in these great libraries devoted to science and public study has nothing to find, and therefore nothing to seek. I have thus been compelled to procure the materials I wanted partly through the kindness of friends and acquaintances, and partly by purchase of books--often at considerable expense,--but always by roundabout means and with great difficulty. And here I should like specially to emphasise the fact that it was the literary representatives of Anarchism themselves who, although I never concealed my hostility to Anarchism, placed their writings at my disposal in the kindest and most liberal manner; and for this I hereby beg to offer them my heartiest thanks, and most of all Professor Elisee Reclus, of Brussels.