Maharishi-''a science is a systematic investigation by means of repeatable experiment to gain useful and testable knowledge

but

The traditional definitions taught to us 

a branch of knowledge or

 study dealing with a body of facts or truths systematically arranged and showing the operation of general laws: the mathematical sciences.

systematic  knowledge of the physical or material  world gained through observation and ;experimentation.

any of the branches  of natural or physical science.

systematized knowledge in general.

knowledge, as of facts or principles; ;knowledge gained by  systematic study.

In these definitions science is defined as body of knowledge , as if , it's a frozen finality , and one has to simply know it, ie mug it up and and become ''scientist''--the most injustice done to the word science 

if you apply to spirituality--it again says a knowledge that is already made known ---and makes us to face a dead end 

where as maharishi has made it clear as---a systematic investigation'' --meaning that there is a lot more to go, knowing more and more, that is how science is advancing, not standing still.

applying this to spirituality, 

knowing is a process, it is a seeing process, a rishi aspect, seeing deeper and deeper aspects , discovering unending laws of nature .thus opening a vast vista to boundless ocean of knowledge .

so the defining science more completely, more precisely makes the journey unblocked by already known things , man is free to explore more, newer avenues