Charity and tax deductions – does it defeat the purpose of charity?

When you make a charitable donation you are able to claim it on your taxes and you receive a deduction.

This would obviously be a benefit and urge some people to donate more, but to me I feel it defeats the purpose of "charity." I always thought of charity as a give something for nothing in return sort of deal… but maybe I am wrong?

Do you feel as though tax deductions for charity is defeating the purpose of the meaning and integrity of charity?

Can I consider donations from last year as deductions on this years tax forms?

I forgot to add many of my charitable donations to my tax deductions last year. Am I allowed to file them as donations if I did not claim them as such last year?

Also, what can be considered a charitable donation? What about costs associated with doing it? Like transportations?