SAN FRANCISCO — The Greek philosopher Aristotle described man as a rational animal. If only software were so easy to define.
On the witness stand in the federal courthouse here Thursday morning,Larry Page, the chief executive of Google’s parent company, Alphabet, offered metaphysical musings regarding the nature of software as a lawyer for Oracle Corporation questioned him about the creation of the world’s most popular smartphone operating system, Android.
Oracle says Google, the search giant, uses copyrighted material in 11,000 of its 13 million lines of software code in Android, and wants $9 billion from Google. Google says it made fair use of that code and owes nothing.
Mr. Page, known for his love of big technology ideas, questioned whether lines of software that declare how the rest of its actions will work are really software.
“For me, declaring code is not code,” he said, offering a philosophical view of software that may be common among Google engineers but stands a good chance of confounding nearly everyone else.
With jury deliberations expected to start next week, whether it makes sense to nontechies that Google, as Mr. Page contends, engaged in “established industry practice” and not old-fashioned copyright infringement could have a significant impact on how the technology industry creates new products.
The copyrights that are crucial to the trial are related to open-source software, which is created and shared for general use. Open-source technology is at the heart of many current innovations, from Google’s Android to the hardware going into giant cloud-computing data centers.
“The open-source community will heave a huge sigh of relief if Google wins, and will be very worried if Oracle wins,” said Pamela Samuelson, professor of law at the University of California, Berkeley. “It will have a chilling effect.”
Should Oracle prevail, Mr. Page could lose a significant chunk of his company’s $75.3 billion in cash. Since Android became a product in 2007, Oracle estimates Google has made $21 billion in profit from it. A verdict in favor of Oracle could also lead to a new way for older companies that built giant businesses from licensed software to make money.
Speaking on the witness stand earlier in the week, Safra A. Catz, the co-chief executive of Oracle, called Java, the open-source product Google is accused of taking, “the single most important asset Oracle acquired” in its 39-year history, and spoke of billions in lost revenue as a result of Google’s actions. Oracle picked up Java when it purchased Sun Microsystems for $7.4 billion in 2010.
The fight between Oracle and Google began that year as a patent and copyright dispute, and in one phase or another it has involved many of the best-known names of Silicon Valley.
The initial case was decided largely in favor of Google in 2012, and the patent claims were dismissed. But in 2014 a federal appeals court found certain parts of Java were protected by copyright. When the Supreme Court refused to hear an appeal of that decision last year, the case was sent back to federal court.
This trial, which began last week, has followed a tangle of careers as well as code. Eric Schmidt, the executive chairman of Alphabet, testified on his time working on Java when he was at Sun, and his knowledge of Apple’s iPhone developments when he sat on the Apple board. Andy Rubin, who led the Android efforts at Google and also testified, had worked at Apple early in his career, and used Java at Danger, another phone company he co-founded. Mr. Rubin has since left Google, and is working on robots and artificial intelligence.
Lawrence J. Ellison, co-founder and now executive chairman of Oracle, appeared in a taped deposition about acquiring assets of Sun. Though it was not mentioned in the testimony, Sun fell on hard times after the dot-com boom largely because of competition from another open-source software project, Linux.
Mr. Ellison was also close friends with Steven P. Jobs, Apple’s co-founder, who was outraged when Google revealed its plans for an iPhone competitor that looked a lot like the iPhone.
There were even glimpses of frosty social exchanges. Ms. Catz testified to running into Google’s corporate lawyer at a bat mitzvah. “‘Google is a very innovative company,’” she recalled him saying. “‘The old rules do not apply to us.’”
“I immediately said, ‘Thou shalt not steal,’” she said on the stand.
The jury was allowed to spend the weekend with what appeared to be notebooks full of notes on code, corporate strategy and the economics of software. Whatever the jurors decide, both sides have indicated another appeal is likely.
Ultimately, Ms. Samuelson said, the Supreme Court should hear some aspect of the case, if only to clarify what she termed “incredibly important, the first significant software copyright case in 10 years.”