It may fairly be asked, and no doubt will, how I dare to set up my opinions with regard to these monuments in opposition to those of the best informed antiquaries, not only in this country but on the Continent? The answer I would venture to suggest is, that no other antiquary, so far as I am aware, has gone so carefully and fully into the whole subject, or has faced all the difficulties with which the questions are everywhere perplexed. The books that have hitherto been written are either the work of speculative dreamers, like Stukeley, Higgins, or Vallancey, who having evolved a baseless theory out of their own inner consciousness, seek everywhere for materials to prop it up, and are by no means particular as to the inferences they draw from very obscure or slender hints: or they are, on the other hand, the works of local antiquaries, whose opinions are influenced mainly by what they find in their own researches. The works of such men are invaluable as contributions to the general stock of knowledge, but their theories must be received with caution, as based on too narrow a foundation either of facts or inferences; for it need hardly be insisted upon that no amount of local experience can qualify any one to write on such a subject as this. It does not even seem sufficient that an author should be familiar with all the varieties of megalithic remains. Unless he has also mastered the other forms of architectural art, and knows in what manner and from what motives the styles of one people are adopted from or influenced by that of another race, he will hardly be able to unravel the various tangled problems that meet him at every step in such an investigation. When looked at, however, from the same point of view, and judged by the same laws as other styles, that of the dolmen builders does not appear either mythical or mysterious. They seem to be the works of a race of men actuated by the same motives and feelings as ourselves, and the phenomena of their arts do not seem difficult of explanation.