I love the argument from authority they make. "Gerald Heard"? Who is he to decide that it is a "truism" that nobody can look at the world without being concerned? So I wikipedia'd the man.
He maintained a regular discipline of meditation, along the lines of yoga, for many years. In the 1950s, Heard tried LSD and felt that, used properly, it had strong potential to 'enlarge Man's mind' by allowing a person to see beyond his ego.
Does the WTS really want to be taking viewpoints from someone who does yoga and is on LSD? (Well, was, the man is dead now, obviously.)
After quoting some more people, they just blindly assert that these are "clear-thinking men". But isn't that the question of reader? That it's just alarmist talk? The WTS just say "NO!" and doesn't actually give any evidence whatsoever. On the contrary, it continues to talk about "the moral breakdown of Christianity" - when this was never even hinted at, neither in the question, nor in the quotations, nor even in the bible - a book which is bullshit anyway.
Close off with some threats and fearmongering and call it a day.