Yogasūtra I.39 - yathā abhimata dhyānāt vā

Or through meditation on any appropriate focus [the mind will be calmed].

Sometimes the simplest objects of inquiry, such as the first cry of an infant, the chirping of the birds, the sound of the waves or a piece of art, can help silence our mental disturbances. Often we get engaged in complex inquiries and get lost in them, to the extent that we lose our focus on reaching the state of Yoga. That is why Pataïjali reminds us here that any appropriate focus that helps to take our mind from distraction to direction must be considered. 

Furthermore, by allowing us to choose any appropriate focus, Pataïjali  demonstrates that his system is indeed universal and non-dogmatic.