Lord Buddha did not give them the information of the subtle body, or the soul. They are unable. Why they were unable? They were gross materialists.
The gross materialists, they are animal-killers, gross materialists. That . . . these animal-killers, according to Bhāgavata also, they cannot understand finer things. Those who are animal-killers and animal-eaters, they cannot understand finer philosophical matter. Their brain is gross. Therefore they are much inclined to mechanical way of life. Machine. Machine is gross. You see? We therefore forbid our students not to be meat-eaters, because by refraining yourself from meat-eating, you will have . . . you will develop finer . . . not only refraining from meat-eating. That is one of the condition. There are other conditions also, but this is one of the condition.