Christian contemplation is defined by writers like St. Augustine, St. Bonaventura, St. Teresa, and St. John of the Cross.
Things evidently started to go wrong around the time of Thomas Merton. I enjoyed his first books, including "Seeds of Contemplation," but he went off the rails. As you may know, he was killed by an electric shock in his hotel room while attending a Buddhist convention in Asia in the interests of ecumenism.
In fact I know one scholar who wrote an excellent book on the mystical poetry of Henry Vaughan, then got involved with LSD, and wrote a second book comparing Christian contemplation with acid trips. No, they are not the same.