user8159: How can I purify my mind so that I can gain confidence and believe that I can study and practice efficiently? The major hindrance for that, what I believe, is that my subconscious mind is strongly saying that I am incapable.

user10293: It is just simple. The hierarchy is sila(at least five precepts for lay man),Samadhi(concentration),and insight knowledge. To achieve this in order, the very first thing is one's strong believe in Dhamma and the meditation master who can teach you in every detail. Just like inertia, if one not yet start , it is difficult to do so. But one of the encouraging fact is the will to do so if one has, it the very beginning. Throughout Sansara, all these defilement clinging to one mind but insight meditation if properly done no matter one has all the misdeeds except the great five ones. So as a very step go to a retreat you rely on where you can find a god master, and start this hierarchy relentlessly at least for 2 weeks. If you have the basic after that you can proceed at home whenever you find time. As mentioned earlier, just to start. If concentration moment accumulate from second to minute to hour , you will find the progress.

user295: This is one of the Hindrances which is Doubt. The best way to overcome this is wise attention, i.e., see through vipallasa by means of Vipassana as mentioned in the other answer. [Nīvarana,pahana Vagga, Yoniso Manasikāra Sampadā Sutta, Vipallasa Sutta].
Also see: Nīvaraṇa by Piya Tan, The 5 Mental Hindrances by Piya Tan, 

8159: <p>How can I purify my mind so that I can gain confidence and believe that I can study and practice efficiently? The major hindrance for that, what I believe, is that my subconscious mind is strongly saying that I am incapable.</p>
 10293: <p>It is just simple. The hierarchy is sila(at least five precepts for lay man),Samadhi(concentration),and insight knowledge. To achieve this in order, the very first thing is one's strong believe in Dhamma and the meditation master who can teach you in every detail. Just like inertia, if one not yet start , it is difficult to do so. But one of the encouraging fact is the will to do so if one has, it the very beginning. Throughout Sansara, all these defilement clinging to one mind but insight meditation if properly done no matter one has all the misdeeds except the great five ones. So as a very step go to a retreat you rely on where you can find a god master, and start this hierarchy relentlessly at least for 2 weeks. If you have the basic after that you can proceed at home whenever you find time. As mentioned earlier, just to start. If concentration moment accumulate from second to minute to hour , you will find the progress.</p>
 295: <p>This is one of the <a href="https://en.wikipedia.org/wiki/Five_hindrances" rel="nofollow noreferrer">Hindrances</a> which is <a href="https://en.wikipedia.org/wiki/Vicikitsa" rel="nofollow noreferrer">Doubt</a>. The best way to overcome this is wise <a href="https://en.wikipedia.org/wiki/Manasikara" rel="nofollow noreferrer">attention</a>, i.e., see through vipallasa by means of <a href="https://en.wikipedia.org/wiki/Vipassan%C4%81" rel="nofollow noreferrer">Vipassana</a> as mentioned in the other answer. [<a href="http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2009/12/16.3-Nivarana-Pahana-Vagga-a1.2-piya.pdf" rel="nofollow noreferrer">Nīvarana,pahana Vagga</a>, <a href="http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2010/02/34.12-Yoniso-Manasikara-Sampada-S-s45.55-piya.pdf" rel="nofollow noreferrer">Yoniso Manasikāra Sampadā Sutta</a>, <a href="http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2009/12/16.11-Vipallasa-S-a4.49-piya.pdf" rel="nofollow noreferrer">Vipallasa Sutta</a>].</p>

<p>Also see: <a href="http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2010/02/32.1-Nivarana.-piya.pdf" rel="nofollow noreferrer">Nīvaraṇa</a> by Piya Tan, <a href="http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2014/06/0A2-BM2-introduction.pdf" rel="nofollow noreferrer">The 5 Mental Hindrances</a> by Piya Tan, </p>
