Descartes and Plato had a take about how our body corrupt our minds with desires and bodily needs. they even went as far to say that death was the only time our thoughts would be pure and closest to the truth. I think this is false because at the end of the day what fuels your thoughts are your experiences so no matter how well developed your opinions are if they are based on limited material, like social life interactions by example, they will never be completely truthful.