console.log doesn't work in CasperJS' evaluate with setTimeout

Why when I use console.log in evaluate, it works:

casper.then(function() {
  this.evaluate( function() {
    console.log('hello'); 
  });
});

But this doesn't work:

casper.then(function() {
  this.evaluate( function() {
    setTimeout( function() {console.log('hello');}, 1000);
  });
});