Kuzari principle and commonsense

 Chinuch (Comments of author): There is no doubt that the greater number of ancestors who testify about something which they directed experienced that it is more convincing to their children. Therefore, when G d wanted to give the Torah to His people, He gave it in the presence of 600,000 adult males  -  besides the many women and children. This was in order that they could all be faithful witnesses concerning the matter. Furthermore, in order to make the testimony even stronger  -  they all reached the level of prophecy. This is because there is never any doubt concerning that which is known by prophecy…. In fact, if they hadn’t reached the level of prophecy then they might have argued that the wonders that Moshe did before Pharaoh were merely magic tricks… However, after they achieved the level of prophecy, they knew everything that happened was from G d  -  without the slightest doubt. These people who witnessed the events of Sinai with their own eyes and their knowledge resulting from prophecy was the highest possible type available to man  -  testified to their children who were born later that the entire Torah that they had received from Moshe was absolutely true without the slightest doubt. These children then testified to that effect to their children and these children testified to their children throughout the ages…

Rambam (Letter on Astrology): One should not believe something to be true unless it belongs to one of three categories. 1) Something that can be validated by clear proof based upon human reasoning or empirically e.g., arithmetic, geometry or astronomy. 2) Something that can be perceived directly by one of the five senses. For example if he sees something is red or black, or he tastes something is bitter or sweet or he can feel that something is hot or cold… 3) Something which he has received as a tradition from the prophets and righteous people. A sensible person needs to classify everything he believes into that which is based on rational proof, that which he directly perceives with his senses and that which he believes because of valid tradition. Anyone who believes something outside of these three categories is described by the verse (Mishlei 14:15), “A fool believes in everything.”