Personally, I think it's difficult to deny that there is a physiological and scientific aspect to emotions and love. I don't buy the humanist approach. Everything we feel is a product of chemical or electrical activity in our bodies. We may not have it pinpointed yet, but there's a lot we still don't know about the human brain and body. We're working on it, though.
http://health.discovery.com/converge...inginlove.html
http://news.bbc.co.uk/1/hi/health/3261309.stm
http://news.bbc.co.uk/1/hi/health/3236328.stm