Women are weak minded but have greater Binah (understanding)

 Torah Temimah (Devarim 11:19.48) She is not required to learn since we have a rule that all those that others must teach are obligated to learn. It would seems obvious that while there is no obligation for a girl to learn Torah but if she wants to be taught it is permitted. But the truth is that the halacha is that it is prohibited to teach girls Torah. The reason is stated in Sotah (21b) that wisdom leads to slyness and deception and she will end up concealing her transgressions. The Rambam (Talmud Torah 1:13) writes that the reason is that she will end up turning Torah into nonsense. Ultimately all these views are based on the principle that women are naturally weak minded (daatan kalos)

 Torah Temimah (Devarim 11:19.48): The principle that women are weak minded seems to contradict the principle that women  were given extra binah (understanding) . However in truth the characteristics of daas and binah are different. Daas refers to the initial impression that the mind forms while bina is the conceptualization which is developed after careful examination and thinking over a period of time as well as the deductive process of deriving conclusions and the ability for abstract thinking. Therefore even though women  have greater binah than men., but their ability to quickly and accurate grasp new knowledge is inferior. And this is agreed to by scholars. Furthermore those who investigate mental processes write that a person who has a sharp mind has to be extra careful to avoid distorting truth and thus women have a bigger danger of distorting the truth than men because they more easily can construct rationalizations and mistaken views based on weak and flimsy grounds. This is easily readily experienced to be true. This also the meaning of Avos (3:17) if a person is lacking Daas he lacks understanding. That means if a persons facts are weak than the understanding that is developed can not be relied on. So women have a weaker grasp of facts so therefore the conclusions they develop are more likely to be false.