The Gemoro says on 59b - 60a that R'Yochonon is not mechayev someone who gives a flame to a Cheresh/Shoteh/Koton, but is Mechayev him if he gives the materials to make a fire. What is the logic behind this -
1) even if the Koton etc lights the fire, isn't he only back to the stage of having a flame which can burn?
2) if the Koton lights the fire, he has certainly done an independent action, so that the first person should definitely be potur!
Kol Tuv,
Meir Eliezer Bergman, Manchester UK
(1) (a) The Meiri (cited in the Shitah Mekubetzes) writes that the reason that Rebbi Yochanan exempts the person who gave a flame to the Cheresh/Shoteh/Katan is because a flame is liable to die down. Therefore the person who handed over the flame to a Cheresh/Shoteh/Katan did not necessarily hand him a dangerous object.
[This is similar to Reish Lakish's reasoning to exempt the person who gave the Cheresh/Shoteh/Katan a coal, because the latter will extinguish itself without intervention, but Rebbi Yochanan takes it one step further and maintains that a flame will also die out on it's own].
(b) Rabeinu Yehonasan (also cited by the Shitah Mekubetzes) adds that according to Rebbi Yochanan a flame is considered as "Gerama b'Alma" because the flame will not last a moment unless it has a constant supply of sticks.
In contrast if he also gives the Cheresh/Shoteh/Katan materials to make a fire i.e. small sticks and thorns which the flame can very easily catch on to, this is considered that he has directly started the fire (Shitah Mekubetzes in the name of the Meiri and the Ra'ah).
(2) The action of a Katan is not considered as an independent action because a Katan does not possess the intelligence ["Da'as"] to be in full control of what he does. There is a source for this idea in Kidushin 22b. The Gemara there discusses how one does a Kinyan on an animal or an Eved. If one calls an animal and it comes this is considered equivalent to "Meshichah" - pulling the animal - and is an effective way of acquiring the animal because merely calling him is considered as forcing him to come. However if one calls the servant and he comes this is not Meshichah because the Eved comes of his own accord. Rav Ashi added that a minor Eved has the same din regarding this matter as an animal. Rashi DH Katan explains that a minor does not possess Da'as, so calling him to come is considered as forcing him to come and therfore is an effective Kinyan.
Similarly when an adult gives flammible material to a minor this is considered as the action of the adult because the Katan does not possess Da'as.
A Freilichyn Purim!
Dovid Bloom