Jain Digambar sadhus don't wear any colthes. In olden days they used to live in solitary places, so it was O.K. But now a days they come and participate in big gatherings and functions of cities it is very odd and awkward! But they follow their principle!
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If being naked was not ethical, God would have created us wearing clothes. It was humans, who invented clothes for necessity to protect themselves from inclement weather. It remained the same for quite some time. Then came a time when they did not want to be seen naked as they started living in a society which started seeing more in human body than what was meant to be! The more the evolution, the more the dressing up. After some time they clothed themselves from tip to toe. Then followed the time when they started shedding off one by one coming back to "Nudits camps"!! If the sadhus who have foresaken the worldly life, go naked (without feeling the need to cover themselves) it should not matter to any one either ethically or morally. It all depends on what we are trying to see in them rather than how they are dressed. Don;t we come across cases where men have raped even infants!! It is therefore our perception that matters rather than how others are dressed.