Hi. Firstly, I would dispense with the always, in the phrase ‘it always seems probable’.
Secondly, I would start the second sentence with a statement: the main function of ... By starting the sentence with the word ‘this’ you are implying that you have introduced the idea in the previous sentence. When you use pronouns, or words like this and that, be sure to ask yourself what you are referring to. Not making this clear is a common fault in the academic writing of even English first language speakers :)