The Torah (Devorim 15:2,9,10) tells us that a loan between Jews will become voided as a result of Shemita. This means that if the loan was due to be paid before the end of the Shemita year, it will no longer need to be paid. This is viewed as a Torah mandated charity in which the debt is wiped clean.
In the times of the second Temple, the great Hillel encouraged a method by which a loan can be preserved. This is called Pruzbal, which is a contraction of Aramaic words meaning a solution for the rich and the poor. By encouraging this solution the rich would be willing to lend money to the poor without the loan automatically being voided at the end of Shemita (Shulchan Aruch, Choshen Mishpat 67:30).
The function of the Pruzbal is based on a number of principles. Among them: The assumption that the law that loans are voided by Shemita is TEACH613 Pruzbal 2015 001Rabbinic in our times (Shulchan Aruch, Choshen Mishpat 67:1) and that loans in the jurisdiction of a court will not be voided (ibid. 67: 11,18).
The pruzbal procedure resembles is some ways a cross between the procedure of authorizing the sale of Chometz before Pesach, and the hatoras Nidarim procedure of Erev Rosh Hashana. It often involves a Kinyan, a statement in front of 2 or 3 qualified individuals, and a document that gets filled out. Please ask your Rabbinic adviser for guidance. Presented here is a sample Pruzbal as well as a pdf document which you can download.

Capitalism is essentially usury under the term capitalism that forms a kind of misdirection as to call the system a usurious system as it is would have stigmatized it.   Western banks are trying to enter the area of Islamic finance.  It is interesting that the spearhead in Malaysia in favour of Islamic Finance was Dr. Mahathir bin Mohammed.  If you combine his gold dinar currency subject to the Sharia anti-usury laws, you have a system of finance in accordance with the Bible that does not contain within it the Aristotelian flaw explained in the piece "Goethe, Faust and the Euro" below.  The system would be eternal.  This is Islamic finance in theory but not necessarily in practice that will be outlined below.

Vix Pervenit is the last word in Catholicism regarding usury which still formally bans usury as a sin and usury was contemned recently by the Pope though it did not receive much attention (see below the quote).  If you study the investment concept of Buffett on compounding his investment as the secret to his success,  it encompasses the power of compound growth in the investment.   For example, it appears that the Buffett goal is to attain at least a 20% compounded annual rate of return on his investment which on a million dollars over a hundred years compounds at 20% to $82,817,974,522,014.25.  If the rate of growth is 10%, then it comes to $13,780,612,339.82.   Now, if this is purely investment growth, it is licit as this is not usury.   The model, though, gives us a picture of what a usury loan over that period would amount to at the end.

The question then is how do you run a bank with employees if you charge no interest to cover at least the expenses of the charitable lending institution.  We were told by Islamic authorities that the banks do charge this cost in their loans, but some also add other extrinsic charges which end up at about the same level of the contemporary interest rate.   If the loan were restricted to overhead, then under Vix Pervenit it would be regarded as licit under the concept of damnum emergins outlined below.  When we talk about extrinsic charges it means charges that are not part of the intrinsically evil usury which is discussed in detail next.

As an example, we refer to the so-called banks named Monte Pietatis, or Mount of Piety, which were established in the Middle Ages in Italy for poor loans which charged their overhead costs on top of the monetary loan that the Catholic authorities called damnum emergins (direct loss) and this was regarded as extrinsic to the intrinsic evil of usury..   However, the Bible does not make any exceptions in its law for overhead or time consumed by the lender for the purpose of the charitable loan. The Biblical idea is something like you cannot be a little bit pregnant.  It must be interpreted that the Bible does not contemplate a commercial loan without usury as the loan must be released at the end of seven years, and if the loan was made in the sixth year, it was released at the end of the seventh year period, and since all loans could not contain usury, and must be released, this loan and all loans must be understood as as a form of charity.  The Bible does not contemplate commercial loans though they are certainly licit based on adhering to the year of release and the prohibition of usury (and the use of gold but certainly not fiat, fraudulent currency or credit).  

In fact, Signor Antonio in Shakespeare's "Merchant of Venice" undermined the entire usury system by lending commercially without interest though it is doubtful he would have made any loans based on the year of release were it then adopted by the Catholic Church but rather formed licit partnerships. Shylock considered Signor Antonio a threat to his entire usury system as it was his control mechanism over Venetian society as the borrower is the lender's slave (Proverbs 22:7) and wanted his life.  All of western civilization is now enslaved to the .0001% Shylocks.  Many in the Middle East considered the source of the downfall of Saddam Hussein and Muammar Ghaddafi to be that they wished to switch away to gold from the fiat dollar as the ultimate control mechanism (combined with usury) which threatened the Shylocks who in the name of international finance and central banking similarly control the world today.  These are the .0001%.  Plus ca change, plus c'est la meme chose or the more things change the more they stay the same.  

The rationale behind the bank of Monte PIetatis was that no one would loan to the poor under these circumstances which is not too different to the Talmudic thinking that the release provision of the Bible can be circumvented if the loan is made to an abstract institution as a court of law (Pruzbal). 

These thoughts are rebutted by the Bible as follows in Deuteronomy 15 and it is our duty to spend our own time and that of society to make poor loans sufficient for the needy and it is unthinkable that we should charge the poor for this charitable service.  Here is the Biblical quote:

If there be among you a poor man of one of thy brethren within any of thy gates in thy land which the Lord thy God giveth thee, thou shalt not harden thine heart, nor shut thine hand from thy poor brother:
But thou shalt open thine hand wide unto him, and shalt surely lend him sufficient for his need, in that which he wanteth.
Beware that there be not a thought in thy wicked heart, saying, The seventh year, the year of release, is at hand; and thine eye be evil against thy poor brother, and thou givest him nought; and he cry unto the Lord against thee, and it be sin unto thee.
10 Thou shalt surely give him, and thine heart shall not be grieved when thou givest unto him: because that for this thing the Lord thy God shall bless thee in all thy works, and in all that thou puttest thine hand unto.

Deuteronomy 15King James Version (KJV)

15 At the end of every seven years thou shalt make a release.
And this is the manner of the release: Every creditor that lendeth ought unto his neighbour shall release it; he shall not exact it of his neighbour, or of his brother; because it is called the Lord's release.
King James Bible:  Deuteronomy 23:19:
Thou shalt not lend upon usury to thy brother; usury of money, usury of victuals, usury of any thing that is lent upon usury:
Pope Denounces Usury as Inhuman – ZENIT – English
Pope Francis has denounced usury as inhuman, against human dignity and “a dramatic social ill”.
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Vix Pervenit
ON USURY AND OTHER DISHONEST PROFIT Vix Pervenit Encyclical of Pope Benedict XIV promulgated on November 1, 1745.
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Goethe Faust & The Euro – David Lifschultz
We find Johann Wolfgang von Goethe’s Faust in his library in Germany around the late 18th century in a state of manic depression contemplating his forty years spent in the
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