Douglas's reason for citing the First, Third, and Fourth Amendments in his decision was:
He said they created zones of privacy.
Justice Williams Douglas passed a motion in 1965 in response to a suit that was filed against the law about the use of contraceptives in 1879.
The Justice remarked and cited the First, Third, and Fourth Amendments to say that they created zones of privacy that allowed people to decide if they wanted to get pregnant or not, amongst other things.
When Justice Douglas decided to banish the law that was effective in Connecticut, he referred to other Amendments which offered the people privacy and freedom to make their own choices.