Science

"Science is the intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment." - Google Dictionary

"Science is the pursuit of knowledge and understanding of the natural and social world following a systematic methodology based on evidence." - Britain's Science Council

A nice discussion about this topic is given by Khalil A. Cassimally in Labcoat Life.

Carl Sagan has said:

He is the author of one of the best books about science ever written

Neil deGrasse Tyson has a nice quote about belief on science:

Let's not forget about Lesson 1673 though:

Scientific Method

1. Observation and description of a phenomenon or group of phenomena.
2. Formulation of a hypothesis to explain the phenomena.
3. Use of the hypothesis to predict the existence of other phenomena, or to predict quantitatively the results of new observations.
4. Performance of experimental tests of the predictions by several independent experimenters and properly performed experiments.