Finally there are different rules as to the stage at which an attempt begins to be criminal, or as to the distinction between attempts and acts of preparation. The Romans, it is supposed, drew no such distinction.[165] The French law regards as permissible acts of preparation many {244} things which in England would be punished as attempts.[166] In England lighting a match with intent to set fire to a haystack has been held to amount to a criminal attempt to burn it, although the defendant blew out the match on seeing that he was watched. But it was said in the same case that, if he had gone no further than to buy a box of matches for the purpose, he would not have been liable, the act being too remote from the offence to be criminal.[167] "Liability will not begin until the offender has done some act which not only manifests his _mens rea_ but also goes some way towards carrying it out."[168] [Footnote 165: Seeger, _Versuch nach römischem Recht_, p. 49.] [Footnote 166: Chauveau and Hélie, _op. cit._ i. 357 _sqq._ Stephen, _op. cit._ ii. 226.] [Footnote 167: Holmes, _Common Law_. p. 67 _sq._] [Footnote 168: Kenny, _op. cit._ p. 79.] If we go a step further, we come to designs unaccompanied by any attempt whatever to realise them. The laws of all countries agree as to the principle that an outward event is requisite for the infliction of punishment. "Cogitationis p[oe]nam nemo patitur."[169] [Footnote 169: _Digesta_, xlviii. 19. 18.] This fact again illustrates the influence which external deeds exercise upon the moral feelings of men. In the average man moral emotions are hardly ever called into existence by calm and penetrating reflection. There are certain phenomena which for some reason or other are apt to arouse in him such emotions, but he does not seek for them. They must force themselves upon his mind, and the more vigorously they do so, the stronger are the emotions they excite. Nothing makes a greater impression on him than facts which are perceptible by the senses. He will admit that an intention, or even a mere wish, to do something wrong is wrong by itself, but an outward event is generally needed for shaking him up. This, I think, is the original reason why persons have not been punished for intentions unaccompanied by external deeds. No doubt, the principle that "the thought of man shall not be tried," is strongly supported by the fact that, as a mediæval writer puts it, "the devil himself knoweth not the thought of man."[170] But considering how ready people {245} have been to presume guilt in cases of unintentional injuries, it seems very incredible that they originally refrained from punishing bare intentions merely on account of insufficient evidence. Indeed, as an exception to the rule, in a few cases when the crime designed is regarded with extreme horror, the very intention may give such a shock to public imagination as to call for punishment. [Footnote 170: Quoted by Pollock and Maitland, _op. cit._ ii. 474.]